论文标题
Lattice QCD的Pion-Nucleon Sigma术语
The pion-nucleon sigma term from Lattice QCD
论文作者
论文摘要
我们总结了最近的证据，包括晶格QCD和手性扰动理论，这表明高于指望的激发态污染可能是现象学决定性和先前直接的lattice-QCD计算的原因，这可能是pion-nucleon sigma-nucleon sigma sigma sigma sigma sigma term $σ_{πn} $。此外，我们通过计算包括$δ（1232）$共振的校正来扩展$χ$ pt分析，作为明确的自由度。发现这种校正很小，从而证实了$δ$ - 不计算中的激发状态效应，以及$σ_{πn} $的结果。
We summarize recent evidence, both from lattice QCD and chiral perturbation theory, that suggests that larger-than-expected excited-state contamination could be the reason for the tension between phenomenological determinations and previous direct lattice-QCD calculations of the pion--nucleon sigma term $σ_{πN}$. In addition, we extend the $χ$PT analysis by calculating the corrections due to including the $Δ(1232)$ resonance as an explicit degree of freedom. This correction is found to be small, thereby corroborating the excited-state effects found in the $Δ$-less calculation and the result for $σ_{πN}$.
